CONFIG_ARCH_TANGO is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Sigma Designs Tango4 (SMP87xx)

modulename: clk-tango4.ko

configname: CONFIG_ARCH_TANGO

Linux Kernel Configuration
└─>Sigma Designs Tango4 (SMP87xx)
In linux kernel since version 3.10 (release Date: 2013-06-30)  
source code:
drivers/clk/clk-tango4.c


is selected by
CONFIG_TANGOX_WATCHDOG